Surgical intervention is already practiced on patients afflicted with extremely severe obesity (morbid obesity), i.e. in the case of the patient whose weight exceeds, for example the ideal weight of at least 50 kg, by implanting gastroplasty rings in such patients. Such interventions allow not only a series of serious health problems, arising from such overweight, to be avoided, but also and especially to avoid a certain, early death of such patients.
In fact, it is a given fact that patients suffering from morbid obesity see their life expectancy significantly reduced, by at least ten to fifteen years, all the while creating significant psychological burdens. Moreover, a whole series of additional health phenomena are implicated. Their incidence has been implicated in the appearance of additional illnesses such as cardio-vascular illnesses, or even those such as hypertension, diabetes or even severe arthritis.
It is also a given fact that, for such patients, treatments based on strict diets combined with a series of physical exercises, also associated with behavior modification, specifically nutritional, are poorly adapted, even if these treatment methods are acknowledged to be the safest.
This is the reason why effective, long-term treatments for morbid obesity call for surgical intervention.
In general, surgical treatment techniques are recognized that make use of a flaw in the absorption of foodstuffs, i.e. a shortening of the food passage and of digestive successes and techniques making use of a gastric restriction that reduces the size of the stomach.
Surgical techniques implicating a flaw in absorption are those implicating, for example, a “by-pass” technique, or small intestine bypass, or even those implementing a separation of the alimentary passage relative to the digestive successes. These surgical techniques are relatively major and may give rise to severe complications, and this is the reason for which they are almost never used any more now.
Now the tendency is to use surgical techniques which make use of less drastic surgical interventions, such as gastric restriction involving the installation of a gastric ring.
These techniques are now in fairly common use, and for the most part they use, as described for example in patent U.S. Pat. No. 5,074,868, a flexible band of elastomeric material designed to be implanted around the stomach, forming a closed loop defining a fixed pre-established ring diameter, thanks to a closure system. The body of the flexible band comprises a compression cavity or chamber, of variable volume, which is linked to an adjustment catheter allowing injection or extraction of fluid in the compression chamber, so as to cause the internal diameter of the loop to vary, in order to change or adjust the diameter of the stoma. In this way, in combination with the pre-established and fixed ring diameter, which allows adjustment of the stoma diameter and therefore regulation of the quantity of food ingested.
These known devices generally offer satisfaction, but nevertheless have a certain number of drawbacks linked essentially to difficulties stemming from the surgical interventions carried out after installation of the gastric ring. In effect, it has been shown that, in spite of the possibility of being able to modify, to a certain extent, the diameter of the ring without major surgical intervention, thanks to the presence of a miniature case implanted under the skin of the patient, installation of such rings may be accompanied by intolerance phenomena, accompanied for example by vomiting. This may be linked to various causes, and notably to too great a reduction in the diameter of the stoma, or even to an ineffective action of the ring, associated with too great a stoma diameter, or even merely an obstruction, infection or local or general inflammation.
This is the reason why it is often shown to be necessary to once again perform surgical intervention, either to relieve the patient, or to adjust or change the ring implanted previously. Such surgical intervention is particularly severe and most often requires cutting of the ring by a surgeon, along with its changing and replacing.
Finally, such operations are difficult to carry out, difficult for the patient to tolerate, and costly, all the more because they involve destruction and replacement of a ring.
Along with these classic techniques, we also establish a progressive and gradual loss of pressure inside the ring, due to natural osmotic phenomena across the device wall. This necessitates regular interventions in order to readjust the diameter of the ring and contributes to the increased need for the constant surveillance of the patient.
Finally, it has been established that it is possible to use a simple syringe, generally filled with physiological water, to ensure diametric readjustment of the ring by injecting liquid through a subcutaneous case attached to the ring. This is an operation which, because of its simplicity, can escape all medical inspection and be carried out by the patient himself. Optimal safety and control conditions are not, therefore, fulfilled in the case of classical techniques.
To attempt to resolve these drawbacks, a solution has already been proposed, such as that described in the patent application EP-0 876 808. This is a gastric ring that is adjustable in a non-invasive manner, with no patient discomfort, done by remote control, without invasive surgical intervention, by an electromagnetic means implanted in the body of the patient and mounted at least in part on the gastric ring. The means implemented comprise a control box, implanted in the ring and attached to a fluid reservoir, which is also implanted in the body of the patient. With the help of a pump controlled from outside the patient's body through electromagnetic means, it injects or withdraws fluid in the gastric ring in order to adjust its diameter. The entire device is under the control of a means of external control, of the micro-computer type, equipped with an emitter-receiver radio, for example, under the control of the practicing physician.
Such a device, of course, indicates an interesting and beneficial development for patients, but which nevertheless suffers from a certain number of drawbacks linked, in particular, to the need to implant the fluid reservoir directly into the body of the patient. This implantation is delicate and it is difficult to make it watertight, which could present a danger to the patient. Moreover, such a device requires a source of internal energy, for example a battery, implanted in the body itself of the patient, which once again complicates surgical intervention and especially confers a certain fragility upon the system, and could necessitate surgical intervention to change the battery.